Infrastructure Integration ¶

Configuration¶

Use Go's expvar package to expose your memory information

package ...

import (
    ...
    "net/http"
    "expvar"
    ...
)

// If your application has no http server running for the DefaultServeMux,
// you'll have to have a http server running for expvar to use, for example
// by adding the following to your init function
func init() {
    go http.ServeAndListen(":8080", nil)
}

...

// You can also expose variables that are specific to your application
// See http://golang.org/pkg/expvar/ for more information

var (
    exp_points_processed = expvar.NewInt("points_processed")
)

func processPoints(p RawPoints) {
    points_processed, err := parsePoints(p)
    exp_points_processed.Add(points_processed)
    ...
}

...

Configure the agent by editing /etc/nutanix/epoch-dd-agent/conf.d/go_expvar.yamlin the collectors.

Example:

    init_config:
    instances:
      # Most memstats metrics are exported by default
      # See http://godoc.org/runtime#MemStats for their explanation
      # Note that you can specify a `type` for the metrics. One of:
      #  * counter
      #  * gauge (the default)
      #  * rate (note that this will show up as a gauge that is meant to be seen as a "per second rate")

      - expvar_url: http://localhost:8080
        # namespace: examplenamespace         # The default metric namespace is 'go_expvar', define your own
        # tags:
        #   - "application_name:myapp"
        #   - "optionaltag2"
        # metrics:
        #   # These metrics are just here as examples.
        #   # Most memstats metrics are collected by default without configuration needed.
        #   - path: memstats/PauseTotalNs
        #     alias: go_expvar.gc.pause_time_in_ns
        #     type: rate
        #     tags:
        #       - "metric_tag1:tag_value1"
        #       - "metric_tag2:tag_value2"
        #   - path: memstats/Alloc            # metric will be reported as a gauge by default
        #   - path: memstats/Lookups
        #     type: rate                      # metric should be reported as a rate instead of the default gauge
        #   - path: memstats/Mallocs          # with no name specified, the metric name will default to a path based name
        #     type: counter                   # report as a counter instead of the default gauge
        #   - path: memstats/Frees
        #     type: rate
        #   - path: memstats/BySize/1/Mallocs # You can get nested values by separating them with "/"
        #   - path: myvariable
        #     alias: go_expvar.my_custom_name
        #     type: gauge
        #   - path: routes/get_.*/count       # You can use a regex when you want to report for all elements matching a certain pattern

Check and make sure that all yaml files are valid with following command:
```
/etc/init.d/epoch-collectors configcheck
```
Restart the Agent using the following command:
```
/etc/init.d/epoch-collectors restart
```
Execute the info command to verify that the integration check has passed:
```
/etc/init.d/epoch-collectors info
```
The output of the info command should contain a section similar to the following:
```
Checks
======
  [...]
  go_expvar
  ----------
      - instance #0 [OK]
      - Collected 8 metrics & 0 events
```

Infrastructure Datasources¶

Datasource	Available Aggregations	Unit	Description
go_expvar.memstats.alloc	`avg` `max` `min` `sum`	byte	Bytes allocated and not yet freed
go_expvar.memstats.frees	`avg` `max` `min` `sum`	operation	Number of frees
go_expvar.memstats.heap_alloc	`avg` `max` `min` `sum`	byte	Bytes allocated and not yet freed
go_expvar.memstats.heap_idle	`avg` `max` `min` `sum`	byte	Bytes in idle spans
go_expvar.memstats.heap_inuse	`avg` `max` `min` `sum`	byte	Bytes in non-idle spans
go_expvar.memstats.heap_objects	`avg` `max` `min` `sum`	item	Total number of allocated objects
go_expvar.memstats.heap_released	`avg` `max` `min` `sum`	byte	Bytes released to the OS
go_expvar.memstats.heap_sys	`avg` `max` `min` `sum`	byte	Bytes obtained from system
go_expvar.memstats.lookups	`avg` `max` `min` `sum`	operation	Number of pointer lookups
go_expvar.memstats.mallocs	`avg` `max` `min` `sum`	operation	Number of mallocs
go_expvar.memstats.num_gc	`avg` `max` `min` `sum`	garbage collection	Number of garbage collections
go_expvar.memstats.pause_ns.95percentile	`avg` `max` `min` `sum`	nanosecond	95th percentile of recent GC pause durations
go_expvar.memstats.pause_ns.avg	`avg` `max` `min` `sum`	nanosecond	Average of recent GC pause durations
go_expvar.memstats.pause_ns.count	`avg` `max` `min` `sum`	sample/second	Number of submitted GC pause durations
go_expvar.memstats.pause_ns.max	`avg` `max` `min` `sum`	nanosecond	Max GC pause duration
go_expvar.memstats.pause_ns.median	`avg` `max` `min` `sum`	nanosecond	Median GC pause duration
go_expvar.memstats.pause_total_ns	`avg` `max` `min` `sum`	nanosecond	Total GC pause duration over lifetime of process
go_expvar.memstats.total_alloc	`avg` `max` `min` `sum`	byte	Bytes allocated (even if freed)

Infrastructure Integration¶

Configuration¶

Infrastructure Datasources¶

Infrastructure Integration ¶